Yamato's decent character moments are overshadowed by her constant "I'm Kozuki Oden!" shtick that got old really fast. She almost never interacted with the crew, and when she did (during the festival) it was a literal repeat of Carrot arriving at whole cake or Bonney and Luffy looking around Egghead lab. Nothing special. By comparison Tama's interactions with the strawhats are much more unique and actually have emotional weight to them.
Deciding to stay was actually a good character moment for her as Oden's biggest mistake was abandoning Wano to continue his adventure, but yamato fans refuse to admit this because they care more about their joining agenda than about her actual character.